The invention relates to a method for filling a double-wall receptacle, more particularly a double-wall tube, with a solid, fluid or pasty bulk mass, whereby the two chambers of the receptacle are filled at an axially open end of the receptacle. The invention relates likewise to a device for filling a double-wall receptacle in accordance with the preamble of claim 5.
Many applications call for packaging two solid, fluid or pasty bulk material components which are not allowed to intermingle during storage and are not mixed or made use of together until final application. A receptacle suitable for this purpose comprises a double-wall resulting in an inner chamber and outer chamber separated from each other, one example of which is a double-wall tube. For filling the chambers the tube is open at one axial end located opposite the discharge end, i.e. the actual tube opening. Thus, a filler nozzle for filling the chamber with a desired material component may be inserted at this open end into the corresponding chamber. Whilst the inner chamber features a large opening diameter, only a narrow edge portion remains for filling the outer chamber, since the outer chamber is defined on the inner side by the inner wall, of course. One problem in this arrangement is that for filling the outer chamber the filler nozzle is restricted to the spacing of the outer wall from the inner wall as regards its outer diameter. This results in the orifice of this filler nozzle or the thickness of an annular nozzle being corresponding small, as a result of which the filling procedure for the outer chamber is relatively slow. In addition to this problems materialize in inserting the filler nozzle into the outer chamber when a nozzle having a relatively large orifice is to be made use of, this being the reason why the size of the orifice needs to be smaller than the spacing of the inner wall from the outer wall.
It is thus the object of the invention to provide a method which eliminates the aforementioned disadvantages and permits speedy filling of the receptacle. In addition it is an object of the invention to provide a device by means of which a double-wall receptacle can be quickly filled.
The present invention provides a method for filling a double-wall receptacle which includes an inner chamber surrounded by an inner wall and an outer chamber surrounding the inner chamber defined on an inner side by the inner wall and on an outer side by the outer wall of the receptacle, and is open at one axial end for filling. The method comprises deforming the inner wall and/or the outer wall at least in a portion of the open axial end of the receptacle at at least one point transversely to the axial direction, and inserting at least one filler nozzle into the outer chamber at a location of an enlarged distance between inner wall and outer wall.
Due to the invention the inner and/or outer wall is deformed at least in the region of the open axial end of the double-wall receptacle at at least one point transversely to its axial direction. As a result of this the spacing between the inner and outer wall is enlargened at at least one location in the circumferential portion of the outer chamber so that at the location of the largest spacing a filler nozzle can be introduced into the outer chamber, the outer diameter of which is larger than the spacing between the inner wall and outer wall in the original non-deformed circumferential portion. In this arrangement the wall defining each of the chambers may be deformed from without or within, i.e. permitting a force to act on the corresponding defining wall in the direction of the longitudinal centerline of the tube and/or away from the longitudinal centerline of the tube to obtain the desired deformation of the inner or outer wall respectively.
It is now possible by means of the invention to suitably provide a nozzle also for filling the outer chamber which has a larger orifice than would be possible for a non-deformed defining wall of the outer chamber, thus enabling the filling procedure for the outer chamber dictating the filling speed and thus the filling procedure in all to be accelerated.
In one advantageous aspect of the method a body is inserted into the inner and/or outer chamber, the shape of the body dictating the deformation of the inner or outer wall respectively. The degree of deformation in this arrangement is advantageously made dependent thereof how far the body is inserted into the chamber. In the filling procedure a narrow end of the body is first inserted into the inner and/or outer chamber. When the body is then urged deeper into the chamber, it deforms the defining wall of the chamber increasingly and the nozzle can then progress further into the chamber where the spacing between the inner and outer wall has been increased by the deformation. A further advantage of inserting a body into the inner and/or outer chamber consists of the double-wall receptacle being maintained in a fixed position by this body during filling.
In a further advantageous embodiment of the method it is possible to insert a body into the inner and/or outer chamber, the shape of the body being variable. The inner and/or outer wall is then first deformed by the change in shape of the inserted body after the body has attained its final position in the corresponding chamber.
The method in accordance with the invention in this arrangement is not restricted to a specific number of points of deformation. Thus, the double-wall tube can be deformed at two points of the inner wall which are preferably spaced away from each other by 180xc2x0 relative to the longitudinal centerline of the tube. Likewise, the tube may be deformed to advantage at three points of the inner wall each of which is then spaced 120xc2x0 away from this longitudinal centerline.
The filling device in accordance with the invention then comprises an element or a body which deforms the inner and/or outer wall at least in the region of the open axial end of the receptacle at at least one point transversely to the axial direction. This may be e.g. an element which is forced against the receptacle from without. Preferably this element is a body which is inserted into the inner and/or outer chamber to deform the inner and/or outer wall. All that is important for the deformation in this arrangement is that the body has a shape in the plane perpendicular to the longitudinal centerline of the tube which is otherwise relative to the defining wall of the chamber to be filled, as a result of which the spacing between the inner wall and the outer wall at at least one location of the circumferential portion is larger than in the original non-deformed circumferential portion. Because of this, the filling device in accordance with the invention comprises a filler nozzle, the outer diameter of which is larger than the spacing between the inner wall and the outer wall in the originally non-deformed circumferential portion of the outer chamber.
The body is suitable shaped conically in the longitudinal centerline of the direction of movement, similar to a cone or a wedge to ensure targetted insertion of the body into the inner and/or outer chamber.
It may be likewise of advantage to provide a device which varies the shape of the body so that the inner or outer wall respectively is first deformed by the change in shape of the inserted body. This may be, for example, a pneumatic device which causes the body to expand by a pressure generated in the interior of the body.
The body comprises preferably a cross-section which dilates the inner wall at two, three or fours points spaced away from each other at an angle of 180xc2x0, 120xc2x0 or 90xc2x0 to the longitudinal centerline of the body on insertion of the body into the inner chamber. Accordingly, the device comprises two, three or four filler nozzles for filling the outer chamber inserted into the outer chamber at the locations precisely between the two, three or four end points.
In another advantageous further embodiment of the invention the nozzle for filling the inner chamber and/or the one or all nozzles for filling the outer chamber is/are integrated in the body, it then being possible to insert the body as well as all filler nozzles with no problem into the chambers of the receptacle in a single operation, the receptacle simultaneously being centered.